JPS5885380A - Compressor for car air conditioner - Google Patents

Abstract

PURPOSE:To prevent the overcooling at the high speed rotation of a car airconditioner, by providing a valve device for controlling the refrigerant flow in the suction path of a compressor. CONSTITUTION:Under the low speed rotation, the refrigerant gas will flow through the outercircumferential path of a control valve 4 and a hole 4a made in the control valve 4, thereby the suction path having sufficient area can be insured. When the rotation exceeds over the desired level, the refrigerant gas flow will increase to increase the pressure loss across the control valve 4 thus to displace the control valve 4 in the direction of flow. The suction gas path area will decrease as the displacement and when reaching to the desired level, the refrigerant gas will flow only through the hole 4a thereby the overcooling of a compressor for a car airconditioner can be prevented.

Description

[Detailed description of the invention] The present invention relates to a compressor for a vehicle air conditioner (hereinafter referred to as a compressor).

), particularly regarding improving performance at high speed rotation.

Generally, this type of air conditioner compressor is driven by the engine, so the rotation speed of the compressor varies over a wide range from several hundred rpm to about 8000 rpm depending on the engine rotation speed. Furthermore, since the displacement per revolution of a compressor does not generally change, the capacity of the compressor exhibits a characteristic like curve A shown in FIG. 1, depending on changes in the number of revolutions. Tsuma6tooor
It increases almost proportionally in the range of pm to g 000 rpm, and the rate of increase gradually decreases in the high speed rotation range.

Of course, there are some differences depending on the type of compressor. On the other hand, in-vehicle air conditioners are generally designed to achieve the desired performance when running at 40 km/hr, and the rotation speed of the compressor in this case is 1500 rpm to 2000 rpm.
It is about pm. Therefore, when actually installed in a vehicle, the air conditioning system operates at a speed of 40 km/Hr-7t, with a compressor rotation speed of 1500 rpm to 2000 rpm, as described above.
Because it is designed to obtain the desired performance, even when driving at high speed.

When the engine speed increases, such as when downshifting.

The rotation speed of the compressor is also high, and the cooling capacity increases.

This has disadvantages in that overcooling occurs, and condensing temperature rises, increasing power consumption and impairing comfort.

The present invention attempts to eliminate the above-mentioned drawbacks by providing a valve device for controlling the flow rate of refrigerant in the suction passage of the compressor.

A detailed explanation of the present invention will be given below with reference to the illustrated embodiments.
Figure 2 is a sectional view of the main parts of the compressor, and (2) shows the suction connection (
2a) and a suction passage (2b), and constitutes the compression element 111. The suction passage (2b) of this drive side housing is connected to the suction passage (2b) of the cylinder (3).
It communicates with 3a). (4) is a control valve according to the present invention, which is provided at the inlet of the suction passage (5a) of the cylinder (3), and is upstream of the flow of refrigerant gas with respect to the valve seat (3b) provided in the cylinder (3). It has an initial displacement in the direction. Further, the control valve (4) is provided with a hole (4a) smaller than the area of the suction passage which becomes the refrigerant gas passage when the displacement becomes zero. In addition, by arbitrarily selecting the plate thickness and length of this control valve (41), desired operating characteristics can be obtained depending on the flow rate of refrigerant flowing through this part. When the control valve (4) has an initial displacement, the vicinity of the valve seat (3b) of the cylinder (31) is connected to the suction passage (3a) of the cylinder (3) so that the refrigerant gas also flows from around the control valve (41). ) and control valve (4).

Next, to describe the operation, as shown in Fig. 3, when the rotation speed of the compressor is low to the rotation speed where the desired capacity is required, the control valve (4) controls the amount of refrigerant gas flowing through the suction passage. The operating characteristics of the control valve (4) are set so that there is almost no change in the initial displacement.

As the refrigerant gas passes through the outer peripheral passage of the control valve (4) and the hole (4a) provided in the control valve (4), as shown by the arrow in the figure,
A necessary and sufficient area can be secured as the suction passage. On the other hand, if the rotation speed of the compressor exceeds the desired value, the amount of refrigerant gas flowing through the suction passage will increase, the pressure loss before and after the control valve (4) will increase, and the control valve (4) will become thicker. (4) K
As the refrigerant gas velocity increases, the control valve (4) is gradually displaced in the flow direction, and the suction gas passage area also decreases with the displacement.

When the desired rotational speed is reached, the displacement of the control valve (4) becomes zero as shown in FIG. In this case, only the hole (4a) provided in the control valve (4) serves as a refrigerant gas passage twl.

Tsumashi, as shown by curve (B) shown in FIG.

Up to the desired rotation speed, it shows the same performance as the conventional case, and when the rotation speed exceeds that, the increase in capacity can be greatly suppressed, achieving highly desirable performance as an on-vehicle compressor. I can do it.

Furthermore, as described above, the operating characteristics of this control valve can be arbitrarily set by adjusting the plate thickness and length of the control valve, so that the performance of the compressor can be arbitrarily controlled depending on the application.

Furthermore, the control valve according to the present invention is capable of automatic and continuous control due to its operating principle.

This is because the 7 demon control valve operates when liquid refrigerant flows.

Since the degree of liquid compression due to liquid return can be greatly reduced, the durability of the compressor can also be greatly improved. In addition,
It is clear that this control valve can be located anywhere between the suction pipe of the compressor and the inlet of the compression element.

Since the present invention is constructed as described above, it is possible to control the capacity of an on-vehicle compressor with a simple device.

Power consumption can be reduced, comfort can be improved, and durability can also be improved.

[Brief explanation of the drawing]

FIG. 1 is a curve diagram showing the performance of a conventional compressor and a compressor according to the present invention according to the rotational speed. FIG. 3 and 4 are enlarged sectional views of essential parts of FIG. 2, showing an example of the operation of the present invention. In the figure, (11 is the compression element, (2a) is the suction pipe t
(2b)-(3a) are 1 suction passage, (41 is control valve #
(4a) is a hole. Agent Shin Kuzuno −

Claims (2)

[Claims] (1) Between the suction passage from the suction pipe of the air conditioner compressor to the inlet of the compression element of the compressor, use a plate spring material or the like to create an initial displacement on the upstream side in the direction of refrigerant flow. , the displacement changes automatically and continuously depending on the flow rate of refrigerant flowing through this suction passage,
A compressor for an on-vehicle air conditioner, characterized in that a valve device has a certain opening area even when the displacement is zero. (2) The compressor for an on-vehicle air conditioner according to claim 1, characterized in that a hole smaller in area than the suction passage is opened in the center of the control valve plate.